Trim Tab Operation

Thanks thataway and ssobol. Your explanations confirm my intuition. My boat operates almost exactly as thataway described. When fully up, the trim tabs are a bit above the water level. I have the LED indicators and I know how to use them. I also have the auto retract feature (which can be annoying when I turn off the key to hear that whine thru its entire cycle even though the tabs are already fully up).

At first, I would get confused because to move the port tab one must use the starboard switch. I intellectually understood why that should be, but it didn't "feel" right. Now it feels natural (push the upper part of the left switch to push down the port bow). My only problem now is that the LED unit is mounted too low for me to see it properly; so I have to crane my neck awkwardly to see it. At some point, I will move that instrument up higher on the helm bulkhead for better visibility.

My motor gauge seems to work exactly as you described thataway. I sometimes have to retrieve at the ramp I use with the prop just out of the water as you mention....I keep my eye on the pee stream. If I remember correctly, the motor switches to the trailering ram just when the needle in the gauge is at 3 o'clock as you mentioned.
 
I disconnected the auto-stow feature on my tabs. Resetting them every time the engine shut off got old. The way my boat sits on the trailer, it is not a issue if the tabs are still down when I retrieve the boat.
 
On the Bennett tabs there is a 22 ga orange wire with an inline fuse holder coming from the controller to power. Just take the fuse out. Since the fuse clips can float in the holder and possibly touch I put an insulated butt splice in place of the fuse. You could put a blown fuse in the holder if you want.

There is also another orange wire without an inline fuse holder. Leave that one alone.

Before doing this, check how your boat rides on your trailer. You do not want to rest the boat on the extended tabs. Removing the auto stow feature can leave you open to this happening if you forget to manually stow the tabs before retrieving your boat. In my case the bunks and the tabs do not align when the boat is on the trailer so it is not an issue for me.
 
Leon":mx0sgy6f said:
Sorry Bob ....the prop runs parallel to the bottom of the boat, it is a constant. On a perfect plane, on smooth water the bow will be slightly higher, and the motor with be a bit forward to the water. if you make the motor parallel to the water, you will be moving it back and a up, it will bring the bow up even higher.
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I will respectfully disagree. Perhaps I should have worded it that the prop thrust, is parallel to the surface of the water. Give the subject a little thought: There is almost always some trim up or down, in respect to the bottom of the boat. It is extremely rare that the prop trust, is parallel to the bottom of the boat. I can go into the theory of this, but it is beyond the scope and space available in this thread.
 
We didn't often use trim tabs. Our previous boat had a Permatrim and with that we trimmed only needing to move the motor with the trim switch on the throttle. We did use trim tabs when taken wind and waves on the front quarter to level the boat when shifting weight around could not get it done. I think in normal situations people might want to take note of where the water is coming off the bottom of the boat by looking out the window at you optimum trim and throttle settings. For us that usually meant seeing water coming out from under the boat in about the helm area in terms of front to back location. When everything is right most can feel the happy zone. The right rpms, trim right for current conditions and load. We seemed to get better mileage at higher speeds as more of the boat is out of the water I guess. Obviously the best mileage comes at displacement speeds.
I think inboard boats rely more on trim tabs as they can't change the attitude of the prop.
D.D.
 
ssobol":ye8dd270 said:
I disconnected the auto-stow feature on my tabs. Resetting them every time the engine shut off got old.
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I did that too. It wasn't so much re-setting them for me, but rather when I'd want to shut down and drift (say I saw some wildlife or etc.) and then instead of silence I'd have to listen to the whole auto-retract sequence. Ugh. So far I haven't missed it, but of course could always re-connect it.

What I'd like is a button (somewhere where I can't hit it accidentally) that, with one press (and no "hold") would just retract both tabs all the way. Sort of like the auto-retract but when I want to, not when "it" wants to). Of course I can press/hold the buttons while they do that, but I'd rather just flip something once and then go about my business (I know, lazy, right? :mrgreen: ) I'm thinking there must be some way to use the (former) auto-retract for that, but have not really looked into it yet.

Speaking of which, another thing I did was to reverse the indicator wires. I can't remember the details anymore, but there was something about how the lights on one side would go along with the opposite tab button that I found counter-intuitive (Bennett indicators). Whatever I did was an easy switch and afterward it instantly made sense to me. Ahhh.
 
This thread is getting old, but not stale! I am relieved to read that some take years to learn how to best utilize their trim tabs. It certainly is not yet intuitive to me. The setup of the toggle switches in relation to the direction the tabs move takes some getting used to. I can see why they are that way; push the top of the starboard switch and the bow and starboard side come up and so on. The problem for me is that the trim tab position indicator lights show where each tab is. My brain automatically compensates for what each tab will do to the boat according to its position and/or change of position. Forcing my brain to ignore the position of the tabs and focus on what a push of a toggle switch does to the boat instead of what it does to a tab and consequently to the boat is taking some time!

Add a Permatrim and motor trim to the equation, and it gets complicated.
 
Rain":5t65lf65 said:
The problem for me is that the trim tab position indicator lights show where each tab is. My brain automatically compensates for what each tab will do to the boat according to its position and/or change of position. Forcing my brain to ignore the position of the tabs and focus on what a push of a toggle switch does to the boat instead of what it does to a tab and consequently to the boat is taking some time!
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I had a similar "disconnect." On the Bennetts, they show you what "the boat will do" vs. what the tab is doing, and that's fine with me (for example the button that affects the port side of the boat is on port side of the panel and is labeled "port" - it's the starboard tab but that affects the port side of the boat). I can see that as a logical choice - after all, that's what we're really trying to do, affect the boat. BUT then, the STARBOARD side lights would display (showing what the TAB was doing, which seemed to undermine the whole "show me what the boat is doing" philosophy). I mean, I can do it either way, but showing me both at once (opposite ways) is just weird (at least for my pea brain).

So, I re-wired the indicator lights to go with the overall philosophy (was simple - I'd have to look at my notes but I think I just reversed the wires on the back of the indicator?). For example, now when I push the button on port side, which is labelled "port" (by Bennett) and affects the port side of the boat, the PORT side row of lights (right next to the button I'm pressing) shows me how much tab is engaged that is affecting that side (right next to the port side button, tidy). My brain is happier with that consistency of presentation. So that's an option for the Bennett indicators.
 
The best way is to observe the way the boat's attitude is, as it runs. Think of bow down and bow up--on each side. Although the lights might seem like a good idea--for many they are confusing.

The only time I found the lights helpful, was on a larger boat than our C Dorys, where there was not the almost instant response there is with any C Dory.

It becomes a reflex, just like balancing a bike, or the helm of a sailboat/tiller of outboard motor--or the wheel of a car or boat...
 
I deliberated quite a bit on the trim-tab indicator lights. I felt, like you, that who cares what the tab is doing - my purpose is to affect the BOAT, and I can/should be able to see what that's doing already. Who needs one more distracting thing in the pilothouse? Just look out the window and/or feel the boat!

But.... at least on the Bennetts, it's a rigamarole to add the indicator lights later, whereas it's no biggie when you are first installing the tabs (which I was). Because of that, after some deliberation I decided to add them to my original install. Turns out, I really like them and am glad I have them (especially after I switched the light wires so they make sense to me).

I still go by what the boat is doing, but I find it interesting to see how much tab it's taking to DO that. (They are not visible like sails are.) And when I have been drifting (for example), I like to be able to see where I left them before running up to speed again (maybe I want to change them - or not - before throttling up). And... sometimes my brain is just confused and likes to see where the tabs are :D May not apply to everyone, but I thought I would mention my experience after going back and forth about it before my initial install of the tabs. It's not like I'd be lost without them, but I am definitely very glad I installed them (easy then; more of a hassle later).

The Auto Retract (it comes bundled with the indicator lights) I hated and disconnected (kind of suspected that would be the case) although I may use that wire for another function at some point in time. Like changing the lights, that was an easy/quick wire switch.

(The reason it's a hassle to add the indicator lights later is that they use a different "head" on the activation arms that are mounted to the outside of the transom. The indicator light head includes wires for such. So to change later you'd have to mess with the arms on the transom/hydraulic tubes, etc. I had the fuel tanks out during the initial install so it was "roomy," but I didn't want to have to monkey with them later once everything was back together - figured if I hated the lights I could just not use them, and changing the wiring around for the way the lights work, the auto-retract, etc. is easy).
 
The operation of the trim tabs makes a bit more sense if you have experience piloting airplanes. Not sure why they did it that way though.
 
I have Lenco Tabs with the lights, and it took a while (long), for me to get the (imho) stupid and totally reversed system using their labeling. I didn't swap the wires like Sunbeam did, but I wish I would have. I now use them like they are labeled and get it, grudgingly.

I like the lights though, reminds me to bring them up and shut them off when I drop from planning to slow cruise or head into the marina, dock or anchorage.

Harvey
SleepyC :moon

JC_Lately_SleepyC_Flat_Blue_070.thumb.jpg
 
Like Sunbeam, I've had the Bennetts with and without indicators. Will never have tabs without indicators again. I've also had Lenco's and Volvo QL's.
I wish the QL's would have caught on better because they are definitely the nicest and easiest to use, and have the cleanest installation. The controls are very intuitive and the service from Volvo was great. Don't know if anyone sells them anymore.
G.P.
 
In short, it doesn't. That fin is for correcting torque steer and the trim tabs (mounted on the hull) are for adjusting hull trim either side to side for leveling, or forward/rearward for overall trim. The up/down trim adjustment on the outboard contributes to the latter but has very little impact on the former. We do not have trim indicators on the 19 but I find the response so clear, that I don't miss them. They are strange to learn but once you have it, indicators seem largely misleading to me without regular resets. I hated the auto retract function at first but now I don't mind it at all. In fact I think cindie likes to use the noise as an indicator that the boat is shutting down when mooring dockside and she is out of the boat.

Greg

more details on adjusting engine steering trim fin-

The setting to neutralize steering torque is different at every engine rpm setting and even engine trim setting.

So, most folks set up the trim on their engine to neutralize steering torque at their normal cruise and normal engine rpm and their normal engine trim setting.

If that is what you want to do, first set the trim tab in the center and lock it down.

Then, take your boat up to your normal cruise, engine rpm and engine trim setting. Then, loosen your grip on the steering wheel and see if the boat wants to go starboard or port. If it stays straight- great, you are set.
If it goes in one direction or the other, make note of the steering direction.

Then, stop the boat, and move the tab to full starboard, or full port and lock it down.

Then, repeat the test and note of the steering direction when you loosen your grip on the wheel.

Then, stop the boat and put the tab to the full opposite direction from the first setting and repeat the test.

Now, you know that for your desired cruise setting, the torque steer amount and direction of full port, center and full starboard setting of the trim tab.

Now, that you have that information, you should be able to dial in the tab in one or two more runs.

Now that you have the trim tab dialed in and if you have a conventional steered boat -i.e. with a single steering tube cable steering, you will have neutral steering at your normal cruise settings.

Of course, if you go slower, faster, just start, or have the engine trim in a different position, the boat will torque steer in one direction or another.

If you have hydraulic steering, most folks either leave the steering tab off of the motor, or just leave it in the center of the motor.
 
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